1. Field of the Invention
The invention concerns a supply unit for an electronic apparatus (in particular a printing apparatus) that can be activated and deactivated. As used herein, a “supply unit” is an internal mains adapter that is used in computers and other electronic apparatuses and that is used in combination with a logic circuit. The supply unit can be deactivated automatically and/or manually to reduce the standby power consumption of such an apparatus without a disconnection from the supply network taking place at the mains. It can be reactivated quickly at any time. As used herein, a “printing apparatus” includes, among other things, a printing device that is equipped to print on flat items to be printed during the passage of the flat items through the apparatus. The invention is suitable for use in franking machines, mail franking systems and other printing apparatuses and mail processing apparatus systems.
2. Description of the Prior Art
It is known to separate an apparatus from a supply network via a mains switch in order to avoid the power consumption by the apparatus when it is not in use. An arrangement to detect the switch position of a mains switch is known from European Patent Application EP 1156405 A2.
EP 1156405 A2 discloses a switching mains adapter combined with a special mains switch and with a logic circuit which, according to the logic state of the circuit, is arranged between the mains switch and a microprocessor of the apparatus.
The mains switch contains two switches connected in series which can be opened or closed only in concert. One switch is connected with one contact thereof to one of the two voltage-carrying lines or neutral lines, and with its other contact is connected with a first input of a sensor that, at its output, transmits an output signal corresponding to the switch setting of the mains switch to a microprocessor of the apparatus. By means of an additional switch in parallel with the mains switch and controlled by the microprocessor, a deactivation delay is achieved without the polling of the switch position of the mains switch being negatively affected by this.
Inkjet print heads are used in modern printing apparatuses. In order to prevent the inkjet print head from drying out when there is no printing or when the apparatus is deactivated, the print head must be moved into a sealed position. In order to ensure that the print heads can still be moved into the sealed position after the activation of the mains switches, the microprocessor transmits a deactivation delay signal for the activation of the aforementioned additional switch.
Requirements for internal mains adapters and Energy Star requirements for the standby power consumption that apply as of 20 Jul. 2007 have been published in the Gazette of the European Union of 28 Dec. 2006 L381/90 under Chapter VIII. SPECIFICATIONS FOR COMPUTERS—REVISED EDITION FOR 2007. The apparatuses must be ENERGY STAR compliant or reach the efficiency values for zero load mode and active mode that are provided in the requirements of the ENERGY STAR program for single voltage-alternating current/alternating current mains adapters and external alternating current/direct current mains adapters. An internal mains adapter is accordingly a component that (for example) is accommodated in a computer housing and serves to convert the alternating current mains voltage into direct current voltage(s) for the power supply of the components of the computer. In the sense of the aforementioned specification, an internal mains part must be mounted within the computer housing but separate from the mainboard of the computer. The mains part must be connected with the mains by a single cable without intervening circuits between the mains adapter and the current mains. All power connections from the mains adapter to the components of the computer must also be accommodated within the computer housing (this means that there may be no external cables from the mains adapter to the computer or to individual components of the computer). Internal direct current/direct current converters that serve to convert a single direct current voltage of an external mains adapter into multiple voltages for the computer do not count as internal mains adapters.
Internal mains adapters must have the following modes:
Sleep mode:
A low consumption mode into which the computer transition automatically after a specific inactivity period or can be manually set. A computer with sleep mode function can quickly be “woken” via network connections or user interface devices.
Standby mode:
(Off) state with the lowest power consumption that cannot be disconnected (affected) by the user, that persists for an unlimited period as long as the apparatus is connected with the mains and is used corresponding to the operating instructions of the manufacturer.
Requirements for stage 2 have applied to power saving functions since 1 January 2009. In addition to the requirements according to stage 1, in ENERGY STAR-compliant computers the complete mains connection in sleep mode must be maintained according to a platform-independent industry standard. Given low data traffic, all computers must reduce their network transfer speeds according to possible industry standards that provide fast transitions between transfer speeds.
In addition to the power saving function, a wake-up event is provided (i.e. an event triggered by the user, a programmed event or external events or pulses) that has the effect that the computer transitions from its sleep or standby mode into its active operating mode. Such wake-up events are, among other things, mouse movements, keyboard inputs or the operation of a button on the housing and—in the case of external events—pulses that are transmitted via remote control, network, modem etc.